the FILTER operation is always checked first if it can be fully evaluated without having to refer to the child operations of the FILTER - and in case of the expression :TEST = this is possible - so the underlying operations won't be started if the expression can be evaluated to FALSE. This could be confirmed by running the same test with rowsource statistics enabled (or via Real-Time SQL Monitoring) - the corresponding skipped child operations should be shown with STARTS = 0.